Some human environments require constant and thorough cleaning as part of its use. One common example are hospital rooms (e.g., exam rooms and surgical rooms), which are disinfected after every use to kill any remaining harmful bacteria and viruses in order to prevent the spread of infection and disease. Cleaning staff work quickly to prepare each room for the next patient. However, cleaning staff must also clean each room thoroughly, which may be difficult if the hospital is facing short turn-around times between patients. In addition, cleaning staff also do not witness the prior activity in the room, and so may not know which surfaces, areas, and objects were used. Therefore, the cleaning staff tends to clean most if not all parts of the room.